Boiler construction



Patented May 29, 1928.

UfNiTEo STATES PATENT y Io'FfFicEe.

WILLIAM R. ,STOCKWELL F MICHIGAN CITY, INDIANA.

BOILER CONSTRUCTION.

Application mea october 19, 1923. `semi No. 669,455.

passageway extending `along the rear wall thereof for establishing,communication Abetween the combustion chamber and the flues, wherein an auxiliary air'inlet is provided at the rear'of the fire box or lire pothaving an opening communicating with the chamber adjacent said passageway, 'of an extent along said rear wall substantially y equal to said passageway, said opening being so 'disposed as to direct air ,upwardly in a continuous sheet to thoroughly mingle with the products of combustion.

VOther objects and advantages of the invention will more clearly appear from the description and claims :hereinafter followinfr.

ktn the drawing forming a part of this specification, Figure 1 is adiametrical, vertical, sectional view, partly broken away, of a boiler, illustrating my improvements in connection therewith. And `Figure 2 is a horizontal, sectional view ofthe back portion of the boiler, corresponding substantially to the line 2-2 of Figure 1.

In said/drawing, indicates a cylindrical base or ashpit section of aboiler, 11 a-cylin- `drical water jacketed 'fire pot section, 12 a water jacketed crown sheet section, 13 a water jacketed dome section, 14 4 a water jacketedrintermediate section, 15 the 'flue between the dome section and the intermediate section, and 16 the Hue between the crown .sheet section l and the intermediate section,

The dome `section 13 is provided with a vertical opening 17, adjacent the'backl of the boiler for establishing communication between the smoke pipe, not shown, and the flue 17, and the section 14 is provided with a vertical opening 17 at the front end thereof for establishingcommunication between the fines 15 and 16, The crown sheet secA tion 12 has an arc shaped opening 18 adjacent the rear wall of the boiler for establishing communication between the flue 16 and' the interiorof the fire pot. The ues 15 and 16 eachhave clean out openings at the front and rear of the boiler, the openings at the' front being closed by .doors 19-19`and the kopenings at the rear being closed by plates .20-20. Communication between the water jackets of the sections 11, 12, 13 and 14 'is established through connecting nipples 2 1. The ash pit section 10 is provided with a grate 22 and the usual ash pit door at the front thereof, not shown, which also serves as the main air supply inlet to admit the air to the fire pot in a well known manner yfor updraft grates.

At the front side, thevfire pot section 11 has the usual clinker door 23 at the bottom thereof. At the top thesection 11 is provid- `opening 24 being 'closed by a door 26 and Vserving asa passage through which the fuel may be fed into-the fire pot.

The opening 25 at the back ofthe boiler in the .section 11 ispreferably of rectangular outline, in elevation, being deiinedby a pair of vertical side walls 27--27 lying in planes radial to the vertical axis of the boiler, a bottom wall 28 disposed in a horizontal plane, and 'the horizontal bottom wall portion'29 of the section 12.

Supported on the wall 28 is an arc shaped block 30 of fire brick or any othersuit'able refractory material, corresponding in length andjheight to the opening v25. The block 30 has-flat, horizontally disposed, top 'and bottom faces 31 and 32, a convex outer face 33, a concave inner face 34, and vertically disposed lat side vfaces 3'5-35 converging `toward the concave inner face 34. The outer and inner faces 33'and 34 of the )block are i rinclined inwardly and upwardly as clearly shown in Figure 1,k Along the louter edge,

the top face 31 bears against the wall 29 ont outer side along ils lower end afs-indicated at 36, thereby providing a shoulder 37. A suitable shoulder 38, extending upwardly from the wall 28 and which may be applied after the block is inserted, holds the block against outward displacement. The block 8() is thus held iii the position shownv in vFigure 1,

projecting inwardly beyond the vertical, in.

ythe same arcuate length the opening 18 of the section 12', as clearly shown iii Figl ure 2. When the bloclr BO is `in position, the

opening at the upper end of the duct is so disposed that the outer wall of the duct registers with the outer wall of the opening 18 in thesection 12, as clearly shown in Figure 1. For convenience of description, I have referred to the bloclr 8O as a unitary structure but, as will be understood by those :skilled in the ar,t,`it may be built into the boiler with bricks or moulded as a single piece. i y u Y y The opening 25 at the upper end of the section 11 is closed by a plate 40" secured to the outer side of the section 11 in any suitable manner, the same being shown in this instance as secured by bolts Lil, the side walls of the opening 25 being suitably cut away to receive the heads ofthe bolts as clearly shown in Figure 2. The plate 10 is provided with a plurality of vertically disposed air inlet openings or slots 42. A transversely slidable shutter 43, having ver tically disposed openings or slots`44., .is adapted to coact with the plate 40 to regulate the amountof air admitted through the openings l2 thereof. The shutter 413 is provided with a centrally disposed knob 45 pro ject-ing therefrom, engaging the kouter side of the plate 40 andhaving the shank thereof working in a transverse slot 4.6 in said plate, the knob serving as a means for manipulat- `ing thesliutter to slide the saine to and fro ings will be completely closed when the shutter is moved to one of its extreme po-` sitions and opened Widest when vmoved to the other extreme position.

diate'position. As clearly shown in Figure y In the draw-` ings, the shutter is shown in the intermel.leading to the iiues of the boiler. The walls of the block between the air duct 39 and the front and rear of the block form baiiies for the incoming air, thereby providing an elongated passageway through .which the air must travel before it `reaches the coinbustion chamber. y

Inasmuch as the boiler is of the `lip-draft type,it will be evident that all the. products of` combustion will necessarily be compelled to pass through the .passageway 18, soine of the productsV of combustion entering said passageway". substantially vertically and others substantially horizontally, due to the iluting or corrugating, ofthe underside of thecrown sheet section 12, as indicated by the shaded lines in Figure 2. This action necessarily induces a swiilingof the prodi" ucts of combustion as they pass through the opening 18and it will be obvious that the greatest heatfroni direct radiation and impingement of the gases will be present immediately adjacent the opening 18 so that the l inner wall ofthe block 30 becomes intensely heated. Asia result of the intensel heat concentrated on theinner walletl the block 30, the supplemental air which is admitted through a tortuous passage, is heated to a relatively high degree and is drawn into the passageway 18at a high velocity and in a continuous arcuate thin sheet; This insures a most thorough inter-niingling` of ,theA

auxiliary air with 'the products of combustion at the most desirable point since coin-V pletion of the combustion takes place both in the upper part of the opening 18 and in the horizontal flue 16.

It will also be noted Ythat/the auxiliary feed arrangement-can be incorporated inthe round sectional type ofboiler without any appreciablel additional expense, since it is only necessary to slightly `modify the fireV pot section 11 by leaving the required opening in the rear wall thereof. All other connections and details of the boiler construction remain unchanged so that the` cost is not adversely affected.

I have herein shown and described what` I nowv consider the preferred manner of carrying out my invention but the saine is merely illustrative and I contemplate all changes and modifications that come within the scope of the claims appended hereto.

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I claim:

l. In a boiler, the combination with a lire pot having an opening through which the fuel may be fed into the interior of the pot; of a water jacketed crown sheet above said fire pot, said crown sheet having an opening therethrough adjacent the wall of the boiler for establishing communication between the interior of the fire pot and a flue -located above the crown sheet; and flue means at the baclr of the boiler, said iue means being entirely exterior to the crown sheet and having an inlet communicating directly with the atmosphere and an Outlet communicating directly with said opening in the crown sheet at the entrance thereof to supply air directly from the atmosphere to said crown sheet opening.

2. In a boiler of the vertical type, the combination with a fire pot having a door through which the fuel may be fed to the interior; of a horizontally disposed, Water jacketed crown sheet section disposed above said fire pot, the said section being provided with a flue opening adjacent the back of the boiler; and an air inlet duct communicating directly with the atmosphere, leading to and terminating at the entrance of said opening, and having an elongated outlet for directing the air upwardly into the entrance of said flue opening inthe form of a continuous sheet.

3. In a cylindrical boiler of the vertical type, the combination with a cylindrical combustion chamber having a top wall providedv with a flue opening communicating with the back of said chamber; of a heatconducting baille element disposed at the rear of said chamber, said baie element being directly exposed to the heat generated within the chamber, a continuous passageway extending through said baffle element and communicating with the combustion chamber and terminating at theentrance to said flue opening; and an inlet port for said passageway opening through the rear of the boiler and communicating directly with the atmosphere.

4. In a sectional boiler of the character described, the combination with a lire pot section having an up-draft grate, said section having an opening at the rear thereof; of a crown sheet section disposed hori- Zontally and on top of the fire pot section, i

the crown sheet section having an arcuate passageway at, the rear side thereof providing communication from t-hc fire pot to flues above the crown sheet section through which the products of combustion are compelled to pass; and an auxiliary air supply device mounted as a unit in said opening of said fire pot section below said passageway in the crown sheet section, said device having a tortuous air passage therein with an exit orifice substantially (zo-extensive in length with said passageway and adapted to direct the auxiliary air supply directly into the entrance o-f said passageway only, said device having an inner wall subject to direct radiation and exposed directly to the current of air in said air passage to thereby insure preheating of the auxiliary air in its Y `passage through said device.

5. In a boiler', the combination with a walled lire pot having an opening through which the fuel may be fed into the interior of the pot and also having an opening I through a walled section thereof; of a crown sheet above the lire pot having a flue thereabove, said Hue having an opening adjacent the back of the boiler communicating with `the interior of the iirecpot; and means for admitting air to said fuel opening, including a member seated in the opening of the walled section and closing the same, said member having a passageway therethrough, the entrance to said passageway directly communicating with the atmosphere andthe exit of said passageway being coincident with the opening of said flue at the point of communication thereof with-the interior of the fire pot.

In witness that I claimthe foregoing I have hereunto subscribed my name this 12th day of October 1923.

WILLIAM It. STOCKW'ELL. 

